1 ------------------------------------------------------------------------------
3 -- GNU ADA RUN-TIME LIBRARY (GNARL) COMPONENTS --
5 -- S Y S T E M . T A S K _ P R I M I T I V E S . O P E R A T I O N S --
9 -- Copyright (C) 1992-2009, Free Software Foundation, Inc. --
11 -- GNARL is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 3, or (at your option) any later ver- --
14 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. --
18 -- As a special exception under Section 7 of GPL version 3, you are granted --
19 -- additional permissions described in the GCC Runtime Library Exception, --
20 -- version 3.1, as published by the Free Software Foundation. --
22 -- You should have received a copy of the GNU General Public License and --
23 -- a copy of the GCC Runtime Library Exception along with this program; --
24 -- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see --
25 -- <http://www.gnu.org/licenses/>. --
27 -- GNARL was developed by the GNARL team at Florida State University. --
28 -- Extensive contributions were provided by Ada Core Technologies, Inc. --
30 ------------------------------------------------------------------------------
32 -- This is a GNU/Linux (GNU/LinuxThreads) version of this package
34 -- This package contains all the GNULL primitives that interface directly with
38 -- Turn off polling, we do not want ATC polling to take place during tasking
39 -- operations. It causes infinite loops and other problems.
41 with Ada
.Unchecked_Conversion
;
42 with Ada
.Unchecked_Deallocation
;
46 with System
.Task_Info
;
47 with System
.Tasking
.Debug
;
48 with System
.Interrupt_Management
;
49 with System
.OS_Primitives
;
50 with System
.Stack_Checking
.Operations
;
52 with System
.Soft_Links
;
53 -- We use System.Soft_Links instead of System.Tasking.Initialization
54 -- because the later is a higher level package that we shouldn't depend on.
55 -- For example when using the restricted run time, it is replaced by
56 -- System.Tasking.Restricted.Stages.
58 package body System
.Task_Primitives
.Operations
is
60 package SSL
renames System
.Soft_Links
;
61 package SC
renames System
.Stack_Checking
.Operations
;
63 use System
.Tasking
.Debug
;
66 use System
.OS_Interface
;
67 use System
.Parameters
;
68 use System
.OS_Primitives
;
75 -- The followings are logically constants, but need to be initialized
78 Single_RTS_Lock
: aliased RTS_Lock
;
79 -- This is a lock to allow only one thread of control in the RTS at
80 -- a time; it is used to execute in mutual exclusion from all other tasks.
81 -- Used mainly in Single_Lock mode, but also to protect All_Tasks_List
83 ATCB_Key
: aliased pthread_key_t
;
84 -- Key used to find the Ada Task_Id associated with a thread
86 Environment_Task_Id
: Task_Id
;
87 -- A variable to hold Task_Id for the environment task
89 Unblocked_Signal_Mask
: aliased sigset_t
;
90 -- The set of signals that should be unblocked in all tasks
92 -- The followings are internal configuration constants needed
94 Next_Serial_Number
: Task_Serial_Number
:= 100;
95 -- We start at 100 (reserve some special values for using in error checks)
97 Time_Slice_Val
: Integer;
98 pragma Import
(C
, Time_Slice_Val
, "__gl_time_slice_val");
100 Dispatching_Policy
: Character;
101 pragma Import
(C
, Dispatching_Policy
, "__gl_task_dispatching_policy");
103 -- The following are effectively constants, but they need to be initialized
104 -- by calling a pthread_ function.
106 Mutex_Attr
: aliased pthread_mutexattr_t
;
107 Cond_Attr
: aliased pthread_condattr_t
;
109 Foreign_Task_Elaborated
: aliased Boolean := True;
110 -- Used to identified fake tasks (i.e., non-Ada Threads)
112 Use_Alternate_Stack
: constant Boolean := Alternate_Stack_Size
/= 0;
113 -- Whether to use an alternate signal stack for stack overflows
115 Abort_Handler_Installed
: Boolean := False;
116 -- True if a handler for the abort signal is installed
124 procedure Initialize
(Environment_Task
: Task_Id
);
125 pragma Inline
(Initialize
);
126 -- Initialize various data needed by this package
128 function Is_Valid_Task
return Boolean;
129 pragma Inline
(Is_Valid_Task
);
130 -- Does executing thread have a TCB?
132 procedure Set
(Self_Id
: Task_Id
);
134 -- Set the self id for the current task
136 function Self
return Task_Id
;
137 pragma Inline
(Self
);
138 -- Return a pointer to the Ada Task Control Block of the calling task
142 package body Specific
is separate;
143 -- The body of this package is target specific
145 ---------------------------------
146 -- Support for foreign threads --
147 ---------------------------------
149 function Register_Foreign_Thread
(Thread
: Thread_Id
) return Task_Id
;
150 -- Allocate and Initialize a new ATCB for the current Thread
152 function Register_Foreign_Thread
153 (Thread
: Thread_Id
) return Task_Id
is separate;
155 -----------------------
156 -- Local Subprograms --
157 -----------------------
159 subtype unsigned_long
is Interfaces
.C
.unsigned_long
;
161 procedure Abort_Handler
(signo
: Signal
);
163 function To_pthread_t
is new Ada
.Unchecked_Conversion
164 (unsigned_long
, System
.OS_Interface
.pthread_t
);
170 procedure Abort_Handler
(signo
: Signal
) is
171 pragma Unreferenced
(signo
);
173 Self_Id
: constant Task_Id
:= Self
;
174 Result
: Interfaces
.C
.int
;
175 Old_Set
: aliased sigset_t
;
178 -- It's not safe to raise an exception when using GCC ZCX mechanism.
179 -- Note that we still need to install a signal handler, since in some
180 -- cases (e.g. shutdown of the Server_Task in System.Interrupts) we
181 -- need to send the Abort signal to a task.
183 if ZCX_By_Default
and then GCC_ZCX_Support
then
187 if Self_Id
.Deferral_Level
= 0
188 and then Self_Id
.Pending_ATC_Level
< Self_Id
.ATC_Nesting_Level
189 and then not Self_Id
.Aborting
191 Self_Id
.Aborting
:= True;
193 -- Make sure signals used for RTS internal purpose are unmasked
198 Unblocked_Signal_Mask
'Access,
200 pragma Assert
(Result
= 0);
202 raise Standard
'Abort_Signal;
210 procedure Lock_RTS
is
212 Write_Lock
(Single_RTS_Lock
'Access, Global_Lock
=> True);
219 procedure Unlock_RTS
is
221 Unlock
(Single_RTS_Lock
'Access, Global_Lock
=> True);
228 -- The underlying thread system extends the memory (up to 2MB) when needed
230 procedure Stack_Guard
(T
: ST
.Task_Id
; On
: Boolean) is
231 pragma Unreferenced
(T
);
232 pragma Unreferenced
(On
);
241 function Get_Thread_Id
(T
: ST
.Task_Id
) return OSI
.Thread_Id
is
243 return T
.Common
.LL
.Thread
;
250 function Self
return Task_Id
renames Specific
.Self
;
252 ---------------------
253 -- Initialize_Lock --
254 ---------------------
256 -- Note: mutexes and cond_variables needed per-task basis are initialized
257 -- in Initialize_TCB and the Storage_Error is handled. Other mutexes (such
258 -- as RTS_Lock, Memory_Lock...) used in RTS is initialized before any
259 -- status change of RTS. Therefore raising Storage_Error in the following
260 -- routines should be able to be handled safely.
262 procedure Initialize_Lock
263 (Prio
: System
.Any_Priority
;
264 L
: not null access Lock
)
266 pragma Unreferenced
(Prio
);
268 Result
: Interfaces
.C
.int
;
271 Result
:= pthread_mutex_init
(L
, Mutex_Attr
'Access);
273 pragma Assert
(Result
= 0 or else Result
= ENOMEM
);
275 if Result
= ENOMEM
then
276 raise Storage_Error
with "Failed to allocate a lock";
280 procedure Initialize_Lock
281 (L
: not null access RTS_Lock
;
284 pragma Unreferenced
(Level
);
286 Result
: Interfaces
.C
.int
;
289 Result
:= pthread_mutex_init
(L
, Mutex_Attr
'Access);
291 pragma Assert
(Result
= 0 or else Result
= ENOMEM
);
293 if Result
= ENOMEM
then
302 procedure Finalize_Lock
(L
: not null access Lock
) is
303 Result
: Interfaces
.C
.int
;
305 Result
:= pthread_mutex_destroy
(L
);
306 pragma Assert
(Result
= 0);
309 procedure Finalize_Lock
(L
: not null access RTS_Lock
) is
310 Result
: Interfaces
.C
.int
;
312 Result
:= pthread_mutex_destroy
(L
);
313 pragma Assert
(Result
= 0);
321 (L
: not null access Lock
;
322 Ceiling_Violation
: out Boolean)
324 Result
: Interfaces
.C
.int
;
326 Result
:= pthread_mutex_lock
(L
);
327 Ceiling_Violation
:= Result
= EINVAL
;
329 -- Assume the cause of EINVAL is a priority ceiling violation
331 pragma Assert
(Result
= 0 or else Result
= EINVAL
);
335 (L
: not null access RTS_Lock
;
336 Global_Lock
: Boolean := False)
338 Result
: Interfaces
.C
.int
;
340 if not Single_Lock
or else Global_Lock
then
341 Result
:= pthread_mutex_lock
(L
);
342 pragma Assert
(Result
= 0);
346 procedure Write_Lock
(T
: Task_Id
) is
347 Result
: Interfaces
.C
.int
;
349 if not Single_Lock
then
350 Result
:= pthread_mutex_lock
(T
.Common
.LL
.L
'Access);
351 pragma Assert
(Result
= 0);
360 (L
: not null access Lock
;
361 Ceiling_Violation
: out Boolean)
364 Write_Lock
(L
, Ceiling_Violation
);
371 procedure Unlock
(L
: not null access Lock
) is
372 Result
: Interfaces
.C
.int
;
374 Result
:= pthread_mutex_unlock
(L
);
375 pragma Assert
(Result
= 0);
379 (L
: not null access RTS_Lock
;
380 Global_Lock
: Boolean := False)
382 Result
: Interfaces
.C
.int
;
384 if not Single_Lock
or else Global_Lock
then
385 Result
:= pthread_mutex_unlock
(L
);
386 pragma Assert
(Result
= 0);
390 procedure Unlock
(T
: Task_Id
) is
391 Result
: Interfaces
.C
.int
;
393 if not Single_Lock
then
394 Result
:= pthread_mutex_unlock
(T
.Common
.LL
.L
'Access);
395 pragma Assert
(Result
= 0);
403 -- Dynamic priority ceilings are not supported by the underlying system
405 procedure Set_Ceiling
406 (L
: not null access Lock
;
407 Prio
: System
.Any_Priority
)
409 pragma Unreferenced
(L
, Prio
);
420 Reason
: System
.Tasking
.Task_States
)
422 pragma Unreferenced
(Reason
);
424 Result
: Interfaces
.C
.int
;
427 pragma Assert
(Self_ID
= Self
);
431 (cond
=> Self_ID
.Common
.LL
.CV
'Access,
432 mutex
=> (if Single_Lock
433 then Single_RTS_Lock
'Access
434 else Self_ID
.Common
.LL
.L
'Access));
436 -- EINTR is not considered a failure
438 pragma Assert
(Result
= 0 or else Result
= EINTR
);
445 -- This is for use within the run-time system, so abort is
446 -- assumed to be already deferred, and the caller should be
447 -- holding its own ATCB lock.
449 procedure Timed_Sleep
452 Mode
: ST
.Delay_Modes
;
453 Reason
: System
.Tasking
.Task_States
;
454 Timedout
: out Boolean;
455 Yielded
: out Boolean)
457 pragma Unreferenced
(Reason
);
459 Base_Time
: constant Duration := Monotonic_Clock
;
460 Check_Time
: Duration := Base_Time
;
462 Request
: aliased timespec
;
463 Result
: Interfaces
.C
.int
;
471 then Duration'Min (Time
, Max_Sensible_Delay
) + Check_Time
472 else Duration'Min (Check_Time
+ Max_Sensible_Delay
, Time
));
474 if Abs_Time
> Check_Time
then
475 Request
:= To_Timespec
(Abs_Time
);
478 exit when Self_ID
.Pending_ATC_Level
< Self_ID
.ATC_Nesting_Level
;
481 pthread_cond_timedwait
482 (cond
=> Self_ID
.Common
.LL
.CV
'Access,
483 mutex
=> (if Single_Lock
484 then Single_RTS_Lock
'Access
485 else Self_ID
.Common
.LL
.L
'Access),
486 abstime
=> Request
'Access);
488 Check_Time
:= Monotonic_Clock
;
489 exit when Abs_Time
<= Check_Time
or else Check_Time
< Base_Time
;
491 if Result
= 0 or else Result
= EINTR
then
493 -- Somebody may have called Wakeup for us
499 pragma Assert
(Result
= ETIMEDOUT
);
508 -- This is for use in implementing delay statements, so we assume the
509 -- caller is abort-deferred but is holding no locks.
511 procedure Timed_Delay
514 Mode
: ST
.Delay_Modes
)
516 Base_Time
: constant Duration := Monotonic_Clock
;
517 Check_Time
: Duration := Base_Time
;
519 Request
: aliased timespec
;
521 Result
: Interfaces
.C
.int
;
522 pragma Warnings
(Off
, Result
);
529 Write_Lock
(Self_ID
);
533 then Time
+ Check_Time
534 else Duration'Min (Check_Time
+ Max_Sensible_Delay
, Time
));
536 if Abs_Time
> Check_Time
then
537 Request
:= To_Timespec
(Abs_Time
);
538 Self_ID
.Common
.State
:= Delay_Sleep
;
541 exit when Self_ID
.Pending_ATC_Level
< Self_ID
.ATC_Nesting_Level
;
544 pthread_cond_timedwait
545 (cond
=> Self_ID
.Common
.LL
.CV
'Access,
546 mutex
=> (if Single_Lock
547 then Single_RTS_Lock
'Access
548 else Self_ID
.Common
.LL
.L
'Access),
549 abstime
=> Request
'Access);
551 Check_Time
:= Monotonic_Clock
;
552 exit when Abs_Time
<= Check_Time
or else Check_Time
< Base_Time
;
554 pragma Assert
(Result
= 0 or else
555 Result
= ETIMEDOUT
or else
559 Self_ID
.Common
.State
:= Runnable
;
568 Result
:= sched_yield
;
571 ---------------------
572 -- Monotonic_Clock --
573 ---------------------
575 function Monotonic_Clock
return Duration is
578 type timeval
is array (1 .. 2) of C
.long
;
580 procedure timeval_to_duration
581 (T
: not null access timeval
;
582 sec
: not null access C
.long
;
583 usec
: not null access C
.long
);
584 pragma Import
(C
, timeval_to_duration
, "__gnat_timeval_to_duration");
586 Micro
: constant := 10**6;
587 sec
: aliased C
.long
;
588 usec
: aliased C
.long
;
589 TV
: aliased timeval
;
592 function gettimeofday
593 (Tv
: access timeval
;
594 Tz
: System
.Address
:= System
.Null_Address
) return int
;
595 pragma Import
(C
, gettimeofday
, "gettimeofday");
598 Result
:= gettimeofday
(TV
'Access, System
.Null_Address
);
599 pragma Assert
(Result
= 0);
600 timeval_to_duration
(TV
'Access, sec
'Access, usec
'Access);
601 return Duration (sec
) + Duration (usec
) / Micro
;
608 function RT_Resolution
return Duration is
617 procedure Wakeup
(T
: Task_Id
; Reason
: System
.Tasking
.Task_States
) is
618 pragma Unreferenced
(Reason
);
619 Result
: Interfaces
.C
.int
;
621 Result
:= pthread_cond_signal
(T
.Common
.LL
.CV
'Access);
622 pragma Assert
(Result
= 0);
629 procedure Yield
(Do_Yield
: Boolean := True) is
630 Result
: Interfaces
.C
.int
;
631 pragma Unreferenced
(Result
);
634 Result
:= sched_yield
;
642 procedure Set_Priority
644 Prio
: System
.Any_Priority
;
645 Loss_Of_Inheritance
: Boolean := False)
647 pragma Unreferenced
(Loss_Of_Inheritance
);
649 Result
: Interfaces
.C
.int
;
650 Param
: aliased struct_sched_param
;
652 function Get_Policy
(Prio
: System
.Any_Priority
) return Character;
653 pragma Import
(C
, Get_Policy
, "__gnat_get_specific_dispatching");
654 -- Get priority specific dispatching policy
656 Priority_Specific_Policy
: constant Character := Get_Policy
(Prio
);
657 -- Upper case first character of the policy name corresponding to the
658 -- task as set by a Priority_Specific_Dispatching pragma.
661 T
.Common
.Current_Priority
:= Prio
;
663 -- Priorities are 1 .. 99 on GNU/Linux, so we map 0 .. 98 to 1 .. 99
665 Param
.sched_priority
:= Interfaces
.C
.int
(Prio
) + 1;
667 if Dispatching_Policy
= 'R'
668 or else Priority_Specific_Policy
= 'R'
669 or else Time_Slice_Val
> 0
672 pthread_setschedparam
673 (T
.Common
.LL
.Thread
, SCHED_RR
, Param
'Access);
675 elsif Dispatching_Policy
= 'F'
676 or else Priority_Specific_Policy
= 'F'
677 or else Time_Slice_Val
= 0
680 pthread_setschedparam
681 (T
.Common
.LL
.Thread
, SCHED_FIFO
, Param
'Access);
684 Param
.sched_priority
:= 0;
686 pthread_setschedparam
688 SCHED_OTHER
, Param
'Access);
691 pragma Assert
(Result
= 0 or else Result
= EPERM
);
698 function Get_Priority
(T
: Task_Id
) return System
.Any_Priority
is
700 return T
.Common
.Current_Priority
;
707 procedure Enter_Task
(Self_ID
: Task_Id
) is
709 if Self_ID
.Common
.Task_Info
/= null
710 and then Self_ID
.Common
.Task_Info
.CPU_Affinity
= No_CPU
712 raise Invalid_CPU_Number
;
715 Self_ID
.Common
.LL
.Thread
:= pthread_self
;
716 Self_ID
.Common
.LL
.LWP
:= lwp_self
;
718 Specific
.Set
(Self_ID
);
720 if Use_Alternate_Stack
then
722 Stack
: aliased stack_t
;
723 Result
: Interfaces
.C
.int
;
725 Stack
.ss_sp
:= Self_ID
.Common
.Task_Alternate_Stack
;
726 Stack
.ss_size
:= Alternate_Stack_Size
;
728 Result
:= sigaltstack
(Stack
'Access, null);
729 pragma Assert
(Result
= 0);
738 function New_ATCB
(Entry_Num
: Task_Entry_Index
) return Task_Id
is
740 return new Ada_Task_Control_Block
(Entry_Num
);
747 function Is_Valid_Task
return Boolean renames Specific
.Is_Valid_Task
;
749 -----------------------------
750 -- Register_Foreign_Thread --
751 -----------------------------
753 function Register_Foreign_Thread
return Task_Id
is
755 if Is_Valid_Task
then
758 return Register_Foreign_Thread
(pthread_self
);
760 end Register_Foreign_Thread
;
766 procedure Initialize_TCB
(Self_ID
: Task_Id
; Succeeded
: out Boolean) is
767 Result
: Interfaces
.C
.int
;
770 -- Give the task a unique serial number
772 Self_ID
.Serial_Number
:= Next_Serial_Number
;
773 Next_Serial_Number
:= Next_Serial_Number
+ 1;
774 pragma Assert
(Next_Serial_Number
/= 0);
776 Self_ID
.Common
.LL
.Thread
:= To_pthread_t
(-1);
778 if not Single_Lock
then
779 Result
:= pthread_mutex_init
(Self_ID
.Common
.LL
.L
'Access,
781 pragma Assert
(Result
= 0 or else Result
= ENOMEM
);
789 Result
:= pthread_cond_init
(Self_ID
.Common
.LL
.CV
'Access,
791 pragma Assert
(Result
= 0 or else Result
= ENOMEM
);
796 if not Single_Lock
then
797 Result
:= pthread_mutex_destroy
(Self_ID
.Common
.LL
.L
'Access);
798 pragma Assert
(Result
= 0);
809 procedure Create_Task
811 Wrapper
: System
.Address
;
812 Stack_Size
: System
.Parameters
.Size_Type
;
813 Priority
: System
.Any_Priority
;
814 Succeeded
: out Boolean)
816 Attributes
: aliased pthread_attr_t
;
817 Adjusted_Stack_Size
: Interfaces
.C
.size_t
;
818 Result
: Interfaces
.C
.int
;
821 Adjusted_Stack_Size
:=
822 Interfaces
.C
.size_t
(Stack_Size
+ Alternate_Stack_Size
);
824 Result
:= pthread_attr_init
(Attributes
'Access);
825 pragma Assert
(Result
= 0 or else Result
= ENOMEM
);
833 pthread_attr_setstacksize
834 (Attributes
'Access, Adjusted_Stack_Size
);
835 pragma Assert
(Result
= 0);
838 pthread_attr_setdetachstate
839 (Attributes
'Access, PTHREAD_CREATE_DETACHED
);
840 pragma Assert
(Result
= 0);
842 -- Since the initial signal mask of a thread is inherited from the
843 -- creator, and the Environment task has all its signals masked, we
844 -- do not need to manipulate caller's signal mask at this point.
845 -- All tasks in RTS will have All_Tasks_Mask initially.
847 Result
:= pthread_create
848 (T
.Common
.LL
.Thread
'Access,
850 Thread_Body_Access
(Wrapper
),
853 (Result
= 0 or else Result
= EAGAIN
or else Result
= ENOMEM
);
857 Result
:= pthread_attr_destroy
(Attributes
'Access);
858 pragma Assert
(Result
= 0);
866 if T
.Common
.Task_Info
/= null then
867 if T
.Common
.Task_Info
.CPU_Affinity
/= Task_Info
.Any_CPU
then
869 pthread_setaffinity_np
872 T
.Common
.Task_Info
.CPU_Affinity
'Access);
873 pragma Assert
(Result
= 0);
877 Result
:= pthread_attr_destroy
(Attributes
'Access);
878 pragma Assert
(Result
= 0);
880 Set_Priority
(T
, Priority
);
887 procedure Finalize_TCB
(T
: Task_Id
) is
888 Result
: Interfaces
.C
.int
;
890 Is_Self
: constant Boolean := T
= Self
;
892 procedure Free
is new
893 Ada
.Unchecked_Deallocation
(Ada_Task_Control_Block
, Task_Id
);
896 if not Single_Lock
then
897 Result
:= pthread_mutex_destroy
(T
.Common
.LL
.L
'Access);
898 pragma Assert
(Result
= 0);
901 Result
:= pthread_cond_destroy
(T
.Common
.LL
.CV
'Access);
902 pragma Assert
(Result
= 0);
904 if T
.Known_Tasks_Index
/= -1 then
905 Known_Tasks
(T
.Known_Tasks_Index
) := null;
907 SC
.Invalidate_Stack_Cache
(T
.Common
.Compiler_Data
.Pri_Stack_Info
'Access);
919 procedure Exit_Task
is
928 procedure Abort_Task
(T
: Task_Id
) is
929 Result
: Interfaces
.C
.int
;
931 if Abort_Handler_Installed
then
935 Signal
(System
.Interrupt_Management
.Abort_Task_Interrupt
));
936 pragma Assert
(Result
= 0);
944 procedure Initialize
(S
: in out Suspension_Object
) is
945 Result
: Interfaces
.C
.int
;
948 -- Initialize internal state (always to False (RM D.10(6)))
953 -- Initialize internal mutex
955 Result
:= pthread_mutex_init
(S
.L
'Access, Mutex_Attr
'Access);
957 pragma Assert
(Result
= 0 or else Result
= ENOMEM
);
959 if Result
= ENOMEM
then
963 -- Initialize internal condition variable
965 Result
:= pthread_cond_init
(S
.CV
'Access, Cond_Attr
'Access);
967 pragma Assert
(Result
= 0 or else Result
= ENOMEM
);
970 Result
:= pthread_mutex_destroy
(S
.L
'Access);
971 pragma Assert
(Result
= 0);
973 if Result
= ENOMEM
then
983 procedure Finalize
(S
: in out Suspension_Object
) is
984 Result
: Interfaces
.C
.int
;
987 -- Destroy internal mutex
989 Result
:= pthread_mutex_destroy
(S
.L
'Access);
990 pragma Assert
(Result
= 0);
992 -- Destroy internal condition variable
994 Result
:= pthread_cond_destroy
(S
.CV
'Access);
995 pragma Assert
(Result
= 0);
1002 function Current_State
(S
: Suspension_Object
) return Boolean is
1004 -- We do not want to use lock on this read operation. State is marked
1005 -- as Atomic so that we ensure that the value retrieved is correct.
1014 procedure Set_False
(S
: in out Suspension_Object
) is
1015 Result
: Interfaces
.C
.int
;
1018 SSL
.Abort_Defer
.all;
1020 Result
:= pthread_mutex_lock
(S
.L
'Access);
1021 pragma Assert
(Result
= 0);
1025 Result
:= pthread_mutex_unlock
(S
.L
'Access);
1026 pragma Assert
(Result
= 0);
1028 SSL
.Abort_Undefer
.all;
1035 procedure Set_True
(S
: in out Suspension_Object
) is
1036 Result
: Interfaces
.C
.int
;
1039 SSL
.Abort_Defer
.all;
1041 Result
:= pthread_mutex_lock
(S
.L
'Access);
1042 pragma Assert
(Result
= 0);
1044 -- If there is already a task waiting on this suspension object then
1045 -- we resume it, leaving the state of the suspension object to False,
1046 -- as it is specified in ARM D.10 par. 9. Otherwise, it just leaves
1047 -- the state to True.
1053 Result
:= pthread_cond_signal
(S
.CV
'Access);
1054 pragma Assert
(Result
= 0);
1060 Result
:= pthread_mutex_unlock
(S
.L
'Access);
1061 pragma Assert
(Result
= 0);
1063 SSL
.Abort_Undefer
.all;
1066 ------------------------
1067 -- Suspend_Until_True --
1068 ------------------------
1070 procedure Suspend_Until_True
(S
: in out Suspension_Object
) is
1071 Result
: Interfaces
.C
.int
;
1074 SSL
.Abort_Defer
.all;
1076 Result
:= pthread_mutex_lock
(S
.L
'Access);
1077 pragma Assert
(Result
= 0);
1081 -- Program_Error must be raised upon calling Suspend_Until_True
1082 -- if another task is already waiting on that suspension object
1085 Result
:= pthread_mutex_unlock
(S
.L
'Access);
1086 pragma Assert
(Result
= 0);
1088 SSL
.Abort_Undefer
.all;
1090 raise Program_Error
;
1093 -- Suspend the task if the state is False. Otherwise, the task
1094 -- continues its execution, and the state of the suspension object
1095 -- is set to False (ARM D.10 par. 9).
1103 -- Loop in case pthread_cond_wait returns earlier than expected
1104 -- (e.g. in case of EINTR caused by a signal). This should not
1105 -- happen with the current Linux implementation of pthread, but
1106 -- POSIX does not guarantee it so this may change in future.
1108 Result
:= pthread_cond_wait
(S
.CV
'Access, S
.L
'Access);
1109 pragma Assert
(Result
= 0 or else Result
= EINTR
);
1111 exit when not S
.Waiting
;
1115 Result
:= pthread_mutex_unlock
(S
.L
'Access);
1116 pragma Assert
(Result
= 0);
1118 SSL
.Abort_Undefer
.all;
1120 end Suspend_Until_True
;
1128 function Check_Exit
(Self_ID
: ST
.Task_Id
) return Boolean is
1129 pragma Unreferenced
(Self_ID
);
1134 --------------------
1135 -- Check_No_Locks --
1136 --------------------
1138 function Check_No_Locks
(Self_ID
: ST
.Task_Id
) return Boolean is
1139 pragma Unreferenced
(Self_ID
);
1144 ----------------------
1145 -- Environment_Task --
1146 ----------------------
1148 function Environment_Task
return Task_Id
is
1150 return Environment_Task_Id
;
1151 end Environment_Task
;
1157 function Suspend_Task
1159 Thread_Self
: Thread_Id
) return Boolean
1162 if T
.Common
.LL
.Thread
/= Thread_Self
then
1163 return pthread_kill
(T
.Common
.LL
.Thread
, SIGSTOP
) = 0;
1173 function Resume_Task
1175 Thread_Self
: Thread_Id
) return Boolean
1178 if T
.Common
.LL
.Thread
/= Thread_Self
then
1179 return pthread_kill
(T
.Common
.LL
.Thread
, SIGCONT
) = 0;
1185 --------------------
1186 -- Stop_All_Tasks --
1187 --------------------
1189 procedure Stop_All_Tasks
is
1198 function Stop_Task
(T
: ST
.Task_Id
) return Boolean is
1199 pragma Unreferenced
(T
);
1208 function Continue_Task
(T
: ST
.Task_Id
) return Boolean is
1209 pragma Unreferenced
(T
);
1218 procedure Initialize
(Environment_Task
: Task_Id
) is
1219 act
: aliased struct_sigaction
;
1220 old_act
: aliased struct_sigaction
;
1221 Tmp_Set
: aliased sigset_t
;
1222 Result
: Interfaces
.C
.int
;
1223 -- Whether to use an alternate signal stack for stack overflows
1226 (Int
: System
.Interrupt_Management
.Interrupt_ID
) return Character;
1227 pragma Import
(C
, State
, "__gnat_get_interrupt_state");
1228 -- Get interrupt state. Defined in a-init.c
1229 -- The input argument is the interrupt number,
1230 -- and the result is one of the following:
1232 Default
: constant Character := 's';
1233 -- 'n' this interrupt not set by any Interrupt_State pragma
1234 -- 'u' Interrupt_State pragma set state to User
1235 -- 'r' Interrupt_State pragma set state to Runtime
1236 -- 's' Interrupt_State pragma set state to System (use "default"
1240 Environment_Task_Id
:= Environment_Task
;
1242 Interrupt_Management
.Initialize
;
1244 -- Prepare the set of signals that should be unblocked in all tasks
1246 Result
:= sigemptyset
(Unblocked_Signal_Mask
'Access);
1247 pragma Assert
(Result
= 0);
1249 for J
in Interrupt_Management
.Interrupt_ID
loop
1250 if System
.Interrupt_Management
.Keep_Unmasked
(J
) then
1251 Result
:= sigaddset
(Unblocked_Signal_Mask
'Access, Signal
(J
));
1252 pragma Assert
(Result
= 0);
1256 Result
:= pthread_mutexattr_init
(Mutex_Attr
'Access);
1257 pragma Assert
(Result
= 0);
1259 Result
:= pthread_condattr_init
(Cond_Attr
'Access);
1260 pragma Assert
(Result
= 0);
1262 Initialize_Lock
(Single_RTS_Lock
'Access, RTS_Lock_Level
);
1264 -- Initialize the global RTS lock
1266 Specific
.Initialize
(Environment_Task
);
1268 if Use_Alternate_Stack
then
1269 Environment_Task
.Common
.Task_Alternate_Stack
:=
1270 Alternate_Stack
'Address;
1273 -- Make environment task known here because it doesn't go through
1274 -- Activate_Tasks, which does it for all other tasks.
1276 Known_Tasks
(Known_Tasks
'First) := Environment_Task
;
1277 Environment_Task
.Known_Tasks_Index
:= Known_Tasks
'First;
1279 Enter_Task
(Environment_Task
);
1282 (System
.Interrupt_Management
.Abort_Task_Interrupt
) /= Default
1285 act
.sa_handler
:= Abort_Handler
'Address;
1287 Result
:= sigemptyset
(Tmp_Set
'Access);
1288 pragma Assert
(Result
= 0);
1289 act
.sa_mask
:= Tmp_Set
;
1293 (Signal
(Interrupt_Management
.Abort_Task_Interrupt
),
1294 act
'Unchecked_Access,
1295 old_act
'Unchecked_Access);
1296 pragma Assert
(Result
= 0);
1297 Abort_Handler_Installed
:= True;
1301 end System
.Task_Primitives
.Operations
;